Methods for detecting electric arcs arising in an installation arrangement are known, during which an attempt is made to detect an electric arc with specific patterns in a frequency spectrum. During such a method, a current and/or voltage signal in the electrical installation arrangement is recorded and analysed. In doing so, it is known that some specific spectral parts are to be analysed as frequency ranges, and the current and/or voltage signal are to be examined with regards to the occurrence of specific patterns in this frequency range, in order to arrive at a conclusion on the occurrence of an electric arc. Such methods have proved to be disadvantageous in practice or unrealistic to implement, as these methods are often unable to detect actually occurring unsafe electric arcs as such, and consequently do not initiate a shutdown of the concerned network in the event of a fault. On the other hand, though, such methods often “detect” safe events as an “unsafe electric arc” and cause a shutdown of the network that cannot be justified from a safety perspective. Therefore, such known methods only ensure insufficient protection against the effects of unsafe electric arcs, and thus do not provide effective protection against fires caused by electric arcs. Furthermore, such methods lead to low network availability on account of inadvertent shutdowns. Due to these considerable disadvantages, such methods are often not used as several users perceive low network availability on account of an inadvertent shutdown as a deliberate disruptive event and negate the risks on account of electric arcs.